Jack operation and maintenance

Yes — every jack must have the manufacturer's rated capacity legibly marked and that rated capacity must not be exceeded. See the requirement in 1926.305(a)(1).

• If a jack has no legible capacity marking, do not use it until the capacity is verified and the jack is clearly marked by the manufacturer or a qualified person. You should also follow the tagging requirements in 1926.305(d)(1)(vi) to take out-of-order equipment out of service.

Each jack must have a positive stop that prevents the jack from overtraveling its intended range. See 1926.305(a)(2).

• Practically, this means the jack must be constructed or equipped so it cannot be raised beyond the safe travel point specified by the manufacturer. Regular inspections should confirm the positive stop is present and working.

The base of a jack must be blocked or cribbed when it is necessary to provide a firm foundation. See 1926.305(c).

• Use blocking or cribbing whenever the surface under the jack is soft, uneven, inclined, or otherwise could allow the jack to shift or settle.
• Blocking/cribbing should be sized and arranged to distribute the load safely and provide stability.

A wood block must be placed between the metal cap of the jack and the load when there is a possibility the metal cap could slip. See 1926.305(c).

• The wood block helps prevent slipping and protects the cap and load contact surfaces.
• Use a solid, properly sized wood block that fits flush and will not crush under the expected load.

No — after a load has been raised it must be cribbed, blocked, or otherwise secured at once; do not rely on the jack as the sole support. See 1926.305(d)(1)(i).

• Always install appropriate cribbing or blocking immediately to transfer the load from the jack to a stable support before performing work under or around the load.

Hydraulic jacks exposed to freezing temperatures must be supplied with an adequate antifreeze liquid. See 1926.305(d)(1)(ii).

• The standard does not define "adequate," so follow the jack manufacturer's instructions for antifreeze type and concentration to ensure safe operation in cold weather.

All jacks must be properly lubricated at regular intervals. See 1926.305(d)(1)(iii).

• The standard does not prescribe a fixed time interval; follow the manufacturer's lubrication schedule and adjust for service conditions (heavy use, corrosive environments, etc.). Regular lubrication prevents premature wear and helps maintain safe operation.

Inspections must be performed at intervals that depend on service conditions, and at minimum as follows: once every 6 months for constant or intermittent use at one locality; when a jack is sent out of the shop for special work (both when sent and when returned); and immediately before and immediately after any use where the jack was subjected to an abnormal load or shock. See 1926.305(d)(1)(iv) and its subparagraphs (a), (b), (c).

• Treat the listed intervals as minimums; increase inspection frequency for harsh service conditions.

For constant or intermittent use at one locality, each jack must be thoroughly inspected at least once every 6 months. See 1926.305(d)(1)(iv)(a).

• Increase inspection frequency if operating conditions (heavy loads, shocks, corrosion, etc.) warrant it.

A jack sent out of the shop for special work must be thoroughly inspected when it is sent out and again when it is returned. See 1926.305(d)(1)(iv)(b).

• Inspecting before sending helps document the jack's condition; inspecting on return confirms it sustained no damage during the special work.

If a jack is subjected to an abnormal load or shock, it must be thoroughly inspected immediately before and immediately after that occurrence. See 1926.305(d)(1)(iv)(c).

• This ensures the jack was fit for service before the event and suffered no hidden damage afterward.

Repair and replacement parts must be examined for possible defects before they are used. See 1926.305(d)(1)(v).

• Practical checks include verifying dimensional fit, checking threads and seals, ensuring no cracks or corrosion, and confirming parts are from the manufacturer or meet manufacturer specifications.

Jacks which are out of order must be tagged accordingly and must not be used until repairs are made. See 1926.305(d)(1)(vi).

• Use a clear out-of-service tag and remove the jack from service or physically secure it to prevent accidental use until qualified repairs are completed.

Immediately inspect the jack thoroughly before any further use, and again immediately after the event; examine any repair parts for defects and tag the jack out-of-order if defects are found until repaired. See 1926.305(d)(1)(iv)(c), 1926.305(d)(1)(v), and 1926.305(d)(1)(vi).

• Do not return the jack to service until a competent person verifies it is safe and any necessary repairs are completed.

If the surface where the jack rests is not firm, the base of the jack must be blocked or cribbed to provide a firm foundation. See 1926.305(c).

• Blocking/cribbing should prevent movement and distribute load; when there is any question about footing stability, err on the side of using proper blocking or cribbing sized for the load.

The text of 1926.305 requires thorough inspections at specified intervals but does not itself prescribe a written recordkeeping requirement for those inspections. See 1926.305(d)(1)(iv).

• Employers may choose to keep written inspection records as part of their safety program to document compliance and to track defects and repairs, even though the section does not explicitly mandate written logs.

You should thoroughly inspect the jack when it is sent out and again when it is returned; specifically, inspect it before reuse after special work. See 1926.305(d)(1)(iv)(b).

• Confirm no parts were damaged or altered during special work and that any replacement parts were examined for defects per 1926.305(d)(1)(v).

Place a wood block between the metal cap of the jack and the load whenever there is a possibility of cap slippage. See 1926.305(c).

• The wood block reduces the chance of slipping and helps protect contact surfaces; size the block so it provides stable, full contact with both the cap and the load.

The standard requires inspections "at times which depend upon the service conditions," so the employer (or responsible competent person) must set inspection frequency based on how the jacks are used and the operating environment. See 1926.305(d)(1)(iv).

• Increase inspection frequency for harsh environments, heavy or shock loading, or other conditions that accelerate wear or damage.